atol.c

来自「mips架构的bootloader,99左右的版本 但源代码现在没人更新了」· C语言 代码 · 共 40 行

/*************************************************************
 * File: lib/atol.c
 * Purpose: Part of C runtime library
 * Author: Phil Bunce ([e-mail])
 * Revision History:
 *	970304	Start of revision history
 */

#include "string.h"

/** long atol(p) converts p to long */
long atol(p)
char *p;
{
int digit,isneg;
long value;

isneg = 0;
value = 0;
for (;isspace(*p);p++) ; /* gobble up leading whitespace */

/* do I have a sign? */
if (*p == '-') {
	isneg = 1;
	p++;
	}
else if (*p == '+') p++;

for (;*p;p++) {
	value *= 10;
	if (*p >= '0' && *p <= '9') digit = *p - '0';
	else break;
	value += digit;
	}

if (isneg) value = 0-value;
return(value);
}